This invention relates to chill-proofing beverages such as beer. The invention involves the use of a combination of silica gel and gelatin to remove various colloidal components of raw beer which form haze upon chilling.
The term "beer" as used in this specification and the claims includes many types of brewed beverages. Such beverages include, but are not limited to, lager, pilsner, Dortmund and Munich beers as well as top fermented beverages such as ale, porter and stout.
Turbidity is an important and at times troublesome aspect encountered in brewing operations. It can be of biological or physicochemical origins. Gross turbidity caused by suspended solids substantially above the colloidal range can be overcome by filtering or other separation methods. Various filter aids called fining agents are used to coagulate such coarse particles. Secondary and more subtle turbidity problems involve the haze which develops on aging and/or chilling the previously filtered beer. This haze is caused by the coagulation of a number of organic materials in the beer. These materials are not removed by the previously described filtration step.
A number of methods have been developed to remove at least some of the chill haze formers in beer. Among these methods are reaction with other organic material to precipitate filtrable compounds. A number of adsorbents are also used to remove certain fractions that cause chill haze. Silica hydrogels and xerogels, calcium, aluminum and magnesium silicates, diatomaceous earth, several types of natural minerals and clays and mixtures thereof have been suggested and used as chill-proofing agents. U.S. Pat. Nos. that disclose such art include the following: 3,163,538; 3,251,693, 3,436,225; 3,617,301; 3,940,498 and 3,958,023. These materials and methods have been successful with some beers but less than satisfactory with other beers.
U.S. Pat. No. 4,109,017 teaches that solids suspended in some fruit juices can be flocculated by using a combination of gelatin and a silica sol. U.S. Pat. No. 4,027,046 teaches that combinations of gelatin and silica sol are not particularly well suited for removing protein fractions from fruit juice and wine. If the silica sol is modified with an aluminum species the combination is more effective. These silica sol-gelatin combinations are directed to turbidity fractions rather than those organics that cause chill haze.
It is an object of this invention to provide a combination of adsorbents that removes a wide range of chill haze components in a wide variety of brewed beverages.